Concussive head trauma has been found to cause many degenerative brain diseases including chronic traumatic encephalopathy (CTE), a degenerative brain disease found in those who have a history of repetitive brain trauma, including concussions.
Individuals with Chronic Traumatic Encephalopathy may show symptoms of dementia, which includes memory loss, aggression, confusion and depression. Such symptoms may appear within months of the trauma or many decades later. CTE has been commonly found in professional athletes participating in contact sports such as gridiron football, ice hockey and professional wrestling. CTE may also result from motor vehicle collisions and battlefield injuries. Most CTE patients have experienced head trauma, resulting in the characteristic accumulation of tau protein and degeneration of brain tissue.
In recent years, professional sports organizations have taken an interest in protecting its players from concussive head trauma. In particular, the efficacy of common sporting equipment is being looked at. Better safety measures and safer helmets are being considered, particularly by the National Football League (NFL) and other professional sports organizations.
U.S. Patent Publication US2009/0265839 to Young et al. is an example of a helmet designed to protect individuals from concussive head trauma. The Young helmet includes a fluid safety liner of closed-cell foam that uses a series of channels and reservoirs to spread concussive forces through the use of viscous fluid flow within the helmet. Protection is afforded by using viscous fluid flow to redistribute peak force during impact. This reduces the biomechanical severity of the impact.
While Young et al. represents a step forward in the art, the mechanical nature of concussive trauma is complex and simple redistribution of impact forces may be insufficient to minimize the biomechanical severity of an impact. Better protection is desired.
The biomechanical effects of impact on the brain should be understood. Severe impact to the skull typically causes the brain to move within the skull. The brain may be pressed against the inside of the skull with sufficient force to damage the brain. Further, once this initial impact is completed, the brain may reverse direction (i.e. bounce), and hit the opposing inside of the skull, thus amplifying the probability of brain damage.
Simply redistributing impact forces as taught in Young et al. may be insufficient to prevent injury due to movement of the brain within the skull after an impact. What is desired is a way of further reducing brain trauma caused by an impact that will minimize harmful movement of the brain within the skull resulting from an impact.